Manufacture of headers or return bends



July 9, 1 935. I I Ns 2,007,649

MANUFACTURE" OF HEADERS OR RETURN BENDS Filed March 17, 1934 '4 Sh etsSheet 1 Fla-8 ATTORNEY July 9,1935. R. K. HOPKINS 2,007,649

MANUFACTURE OF HEADERS OR RETURN BENDS Filed March 17, 1954 4 Sheets-Sheet 2 IN VENTOR we z 23-Ma- ATTORNEY MANUFACTU EEEEEEEE RRRRRRRRRRRR DS Filed March 17, 1934 4 Sheets-Sheet "3 1 Fxa-H N R] N E w'%9 MM I BY/$9411 2am 1935. R. K. HOPKINS 2,007,649

MANUFACTURE OF HEADERS OR RETURN BENDS Filed March 17, 1934 4 Sheets-Sheet 4 Ei'mEl lNVEN/TQQR BY z % TTOIZZEY Patented July 9, 1935 MANUFACTURE OF HEADERS on RETURN BENDS Robert K. Hopkins, New York, N. Y., assignor to M. W. Kellogg Company, New York, N. Y., a corporation of Delaware Application March 17, 1934, Serial No. 716,080

4 Claims. (Cl. 29-157.6)

This invention relates to headers or return By reason of the welding operation an amount of bends for interconnecting the adjacent ends of metal restricts the passageway of the cross-over two or more parallel tubes and is a continuation connection, this metal is removed by a broaching in part of my applications Serial Nos. 645,684 operation, disclosed hereinafter, without perforatand 655,719, filed December 5, 1932 and February ing or otherwise weakening the walls of the 5 8, 1933, respectively. header or return bend. Where a multiple tube 'Headers or return bends of this type are parheader is to be made, forgings as just described ticularly adapted for use in connection with are used at the ends of the header, and intercracking coils and similar oil refining'equipment, mediate forgings having two oppositely disposed although their utility is not limited to this type lateral bosses are welded therebetween. As is 10 of apparatus. The complicated shape of such well understood by those skilled in this art, it is headers or return bends renders it impracticable essential in such headers or return bends to have to produce them commercially by forging in a the centers of the tube bores at a specified dissingle piece. Cast headers or return bends have tance apart, and my invention accomplishes this therefore been employed in spite of the recognized in a simple and expeditious manner. 15 superior strength of forging as compared with My invention may be more clearly understood castings. The superiority of forgings over castby reference to the following description and to ings makes the use of forged headers or return the accompanying drawings, which form apart of bends very desirable in cracking coils because of this specification, and in which:

the extremely high pressures and temperatures Fig. 1 is a central vertical section through a 0 frequently encountered and the subsequent strain die for press forging one of the individual secupon the equipment. tions, the plunger of the press being shown in An object of the invention is to provide a broken lines; method of fabricating unitary headers or return Fig. 2 is a side elevation of a forging made in 5 bends from forged steel, whereby the obstacles the die shown in Fig. 1; heretofore encountered in forging such articles v Fig. 3 is a top plan view of the forging shown are overcome and unitary headers or return bends in Fig. 2; may be produced from forged steel in a simple Fig. 4 is a central vertical section through the and economical manner. 1 forging shown in Figs. 2 and 3 after drilling and According to my invention, a unitary forged cutting; 1 30 steel header or return bend is produced by forg- Fig. 5 is a top plan view of the drilled and cut ing the header or return bend in separate secforging shown in Fig.4; tions, each of which may be forged in a convenient- Fig. 6 is a side elevation showin in full lines and economical manner, subsequently joining two of the drilled and cut forgings in position for these sections by welding in such a manner as to welding to produce a double header, and in broken 35 insure accurate dimensioning of the finished arlines the positions of the forgings after the weldticle and removing the metal in the connecting ing operation is completed; passageway resulting from the welding without Fig. 7 is a top plan view of the parts shown in perforating or otherwise weakening the walls Fig. 6;

of the header or return bend Fabricated in this Fig. 8 is a central vertical section through the 40 manner, the header or return bend, while not finished double header after breaching and maforged as a complete unit, has all of the desirable chining; characteristics of a single forging, and it is gen- Fig. 9 is a side elevation of a modified forging erally more satisfactory than a cast steel header for use in the production of multiple headers;

or return bend, both in point of service and in Fig.10 is a central vertical section through the 45 po t of sa ety. forging shown in Fig.9 after drilling and cutting;

' More specifically, each individual'forging has a Fig. 11 is a central", vertical section through a.

body portion adapted to accommodate a tube and multiple header after the welding operation; a boss extending laterally from the body portion Fig. 12 is a plan view of the header shown in and adapted to form a cross-over connection to Fig. 11; I

the next tube. A forging of this character may Fig. 13 is a sectional view showing a breaching be conveniently and economically made by press apparatus positioned in a header at the beginning forging as disclosed hereinafter. The bosses of of the breaching operation; and two such forgings are then joined together by 'Fig. 14 is a perspective view of various parts 5 welding to form a double header or return bend. of the breaching apparatus of Fig. 13.

Referring more particularly to the drawings, the die shown in Fig. 1 comprises an upper member 2 and a lower member 3 meeting in a horizontal plane at 4. Acylindrical opening 5 extends vertically through the upper member 2 and registers with a cylindrical opening 6 extending part way into the lower member 3 to form a vertical cylindrical recess 1. The vertical cylindrical recess 1 shapes the main body portion of the forging. The members 2 and 3 are also cut away as shown to form a cylindrical recess 8 extending laterally from the vertical cylindrical recess 1. The lateral recess 8 forms a cylindrical laterally extending boss on the forging, and the plane 4 bisects the recess 8 to permit subsequent removal of the forging from the die.

A removable plug 9 has a head l0 fitting snugly in the outer end of the lateral recess 8 and has a cylindrical handle fitting snugly in semicylindrical recesses 2 and I3 in members 2 and 3, respectively. The lower member 3 and the plug 9 are preferably with substantially hemispherical protuberances l4 and I5 located centrally of the closed ends of the vertical cylindrical recess 1 and the lateral cylindrical recess 8, respectively. The protuberance I4 is shown as integral with the lower member 3, but it may if desired be formed by a plug inserted in the member 3. The rear face I 6 of the head l0 and the corresponding end of the recess 8 are preferably shaped like a frustrum of a cone, as illustrated, in order to facilitate separation of the die members from the plug 9 after the forging operation.

A plurality of plugs 9 having heads ID of different thicknesses may be provided, so that a single die I may be used to make forgings having side bosses of different lengths, depending upon the tube center to center distance in the finished header.

In use, the two members of the die I are locked together in a suitable forging press with a plug 9 of suitable dimensions in place, and a heated billet, preferably a short piece of round bar steel stock, is dropped into the vertical recess 1. A plunger 20, shown in broken lines in Fig. 1, is then forced downwardly into the vertical recess 1 of the die, thus forcing the hot metal to occupy all of the recesses and. 8 of the die. The plunger is then raised, the die unlocked, and the upper member 2 raised, leaving the hot forging and the plug 8 resting upon the lower member 3. The forging is now lifted by means of tongs or other suitable implement, carrying with it the inner end of the plug 9 for a short distance until the plug drops out or is extracted laterally.

The forging 2| s0 produced will have the shape shown in Figs. 2 and 3 and will comprise a main cylindrical body portion 22 and a cylindrical side 'boss 23. The length of the boss 23 will depend upon the thickness of the head In of the particular plug 9 chosen. The upper end of the body portion 22 will have a depression 24 corresponding in shape to the plunger 26. The lower end of the body portion 22 and the end of the boss 23 will have depressions 25 and 26, corresponding respectively to the protuberances l4 and I5 of the die member 3 and the plug 9.

Portions of the body 22 of the forging 21 are then cut away, preferably by means of an acety-' lene cutting torch, to form the ears 2! and 28 having slots 28 and 30, respectively, as shown in Figs. 4 and 5. These ears and slots are for the purpose of supporting the customary holding yokes for the closure plugs ordinarily employed in equipment of this kind for sealing the outer ends of the tube bores. It will be understood that the present invention is not concerned with the particular form of closure devices utilized, and that provision might be made for any desired form of such closures. The forging 2| is next drilled to form the tube bore 3| in the body portion 22 and the cross-over connection 32 in the boss 23, as likewise shown in Figs. 4 and 5.

To make a double header, two of the drilled and cut forgings 2| are placed with their bosses 23 facing one another as shown in full lines in Figs. 6 and 7. The ends of the bosses 23 may be then joined together by welding in any desired manner. As stated above, all headers or return bends are made for a definite spacing of the tube centers. The bosses 23 must therefore be of such length that the required distance between the center lines of the tube bores 3| is obtained after the welding operation is completed. If ordinary electric arc welding utilizing a fusible welding rod is to be employed, the ends of the bosses 23 are preferably chamfered so as to form the usual welding groove.

Although electric arc welding may be employed as above described, in the preferred embodiment of my invention I join the two forgings by resistance flash welding. With this type of welding, I make the bosses 23 sufficiently long so that the distance between the center lines of the tube bores 3| is greater at the commencement of the welding operation than is desired in the finished header. Thus, the full lines 35 and 36 in Fig. 7 show the spacing of the center lines of the tube bores 3| prior to welding, and the broken lines 35' and 36 show the spacing of these same center lines after the resistance flash welding operation is completed.

In this resistance flash welding, the welding current is passed directly through the two forgings, and an arc is established between the meet ing faces of the bosses 23 by making contact between the two bosses and then separating them slightly. The are thus established heats the metal at the ends of the bosses, and after a short time this metal begins to melt. The two forgings are then fed slowly towards each other until the distance between the tube bore center lines is a predetermined amount greater than that desired in the finished header. When this predetermined point is reached, the two forgings are pushed rapidly and firmly together until a definite pressure is exerted between them. This last step extinguishes the arc, and the current is cut off after the arc has been extinguished. The extra distance allowed and the pressure to be exerted depend upon the size of the forgings and the welding conditions, and should be determined by experimentation in advance of quantity manufacture. When these factors are properly chosen, the distance between the tube bore center lines of the welded forgings will be within the allowable limits of tolerance.

After the welding operation, the final machining of the header or return bend is performed.

The pressure of the two forgings together produces flashes or upsets 31 and 38 at the inside and outside edges of the bosses 23, as shown in broken lines in Figs. 6 and 7. These flashes or upsets may be seen somewhat more clearly in Figs. l1, l2 and 14. The upsets 31 and 38 may be removed partially or wholly as shown in Fig. 8, the outer upset 31 being removed by chipping or otherwise, and the inner upset 38 by the use of appropriate broaching apparatus.

At present I find that the apparatus shown in of the same diameter as the unrestricted portion of cross-over passageway 32. The endof cutting member adjacent element 46 of minimum diameter is reduced to form a tapered extension 41, the other side is bored to provide recess 48. Align g member 4| includes a middle cylindrical portion of diameter substantially equal to the diameter of cross-over passageway 32, one end portion tapers away from the cylindrical portion and the other end portion is reduced to the size of the end of cutting member 48 that carries tapered extension 41. Aligning-member 4| is bored from the end portion just mentioned to provide a tapered hole of a size to accommodate tapered extensibn 41. Aligning member 42 is 'made up of two semi-cylindrical portions 49 ,and 58 connected by shoulder forming flat surface 5|. .The diameter of portion 49 is substantially equal to the diameter of cross-over passageway 32 and the diameter of. portion 58 is smaller, however, the centers of generation of portions 49 and 5|! are spaced apart so that the diameter of member 42 on the line passing through its center at right angles .to shoulders 5| is substantially equal to the diameter of cross-over passageway 32. One end of member 42 is reduced to form a cylindrical extension 52 of a size to fit in recess 48. The other end of member 42 is fiat and is cut at an angle. Spacing members 43 are similar in shape to member 42 and have both of their ends flat and cut at the same angle as said other end of member 42.

Guide plug. 44 is cylindrical in shape and of a size -to fit the bottom portion of tube bore 3|. The height of plug 44 is such that it extends from the bottom of tube bore 3| to about the'center line of cross-over passageway 32. A slot 53 extends from one side of plug 44 to about its middle and is of a size to accommodate wedge 45. The top of plug 44 has a semi-cylindrical recess 54 therein of a size to accommodate portion 58 of aligning member 42 and spacing members 43. Extending from recess 54 are shoulders 55. which serve to support aligning member 42 and spacing members 43 and permit aligning member -42 and spacing members 43 to slide thereon. Force applying wedge 45 has a hole at its top for connection to the ram 51 of a press or other force applying. means. The angular side of wedge 45 is cut at the same angle as the sides of spacing members 43 and said other side of aligning member-42. I

In carrying .out the broaching the header or return bend, after being welded asabove described, is placed on the platen 58 of a press. Cutting member 40 is then inserted through the top of tube bore 3| into cross-over passageway 32. Aligning member 4| is then inserted into the other end of cross-over passageway 32 through the other tube bore 3| and moved toward cutting member 4|! until extension 41 seats in the tapered recess. Plug 44 is next put in position with the is done aligning member 42 is positioned on plug l5 and moved towards cutting member 48 until extension 52 fits into recess 48. At the end of this step cutting member 40 is properly aligned and supported. The necessary number of spacing members 43 is then placed on shoulders 55 and wedge 45 connected to ram 51 of the press and the press set in operation.

As ram 51 and wedge 45 descend the vertical face of wedge 45 meets the side of the tube bore 3| and the inclined face meets the face of spacing members 43. This results in spacing members 43, aligning member 42 and cutting member 48 being moved axially along in cross-over passageway 32. In displacing the broaching elements just mentioned the vertically directed force of the ram is resolved into two components, one, the horizontal force which moves the broaching member axially and another which pushes spacing members 43 and aligning member 42 into contact with shoulders 55 of plug 44. The reaction of the horizontal component is taken up by the wall of body portion 22 against which wedge 45 contacts. The

reaction of the other component is taken up through plug 44 by the platen 58 of the press.

As ram 51 continues its downward travel the first of cutting members 46 comes into contact with flash 38 and removes a portion thereof to increase its diameter. After this has happened wedge 45 which has approached platen 58 is'retracted and another spacing member 43 added to the one previously put in placefon plug 44.

Ram 51 and wedge 45 are again moved downward to further axially displace thebroaching .ele-

ment. As this further movement goes on the second and third of the cutting members 46 successively come into contact with flash 33 and substantially completely remove it so that at the end of the broaching operation cross-over passageway 32 will beof substantially uniform diameter.

Although I have described the'broaching, as carried on in two downward movements of wedge 45 it is obvious that the cutting away of flash 38 may be accomplished in a'single movement or in more than two movements.

After the return bend or header is broached as above described seats 58 are then machined'very accuratelyto accommodate the customary closure plugs (not shown) and thev tube seats 59 are also machined. accurately not only as to their internal dimensions but so vas to maintain the center to center distances of the tube bores 3| within the required tolerance.

When it is desired to manufacture headers or return bends having provision for more than two tubes, forgingsGll such as shown in Fig. 9, are employed in addition to, the forgings 2|. Forgings 60 may be made in a die similar to that shown in Fig. 1 except that recesses are formed on each side of the vertical cylindrical recesses of the die so that the fo'rgings 6|! will have bosses 6| and .62 on eachof the body portions 63. The forgings 60 after being\. press'ed is drilled and cut in a manner similar to the forgings 2| as shown in detail in Fig. 10. To make a three tube header one forging 68 is placed between two forgings 2| and the whole welded together as shown in Figs. 11 and 12. v The welding operation may be performed in stages, first by welding one end forging to the central forging 68 and then welding. the

made simply by inserting additional forgings 60 between the end forgings 2!. The welded forgings shown in Figs. 11 and 12 should of course be broached and machined subsequently to the .welding operation, described in connection with the production of the header of Fig. 8.

It will be apparent that my invention permits the manufacture of headers or return bends accommodating any desired number of tubes from a plurality of individual forgings each of which may be made in an economical and expeditious manner. Furthermore, my invention permits the welding of these forgings in such manner that accurate centering of the respective forgings is obtained. The resistance welded joint of the preferred modification of my invention is formed wholly from the original forged steel of the forgings, and hence the welded joint has a strength substantially the same as that of the other portions of the finished header. A further advantage of my invention is that headers of varying tube center distances maybe made from the same original forgings, withinreasonable limits, and where extreme variations are desired, this may be accomplished with the die merely by changing the size of the removable plug used during the forging operation.

It will be obvious that various modifications may be made in my invention without departing from the spirit thereof, and I desire to be limited therefore only by the prior art and the scope of the appended claims.

I claim:

1. The process of manufacturing press forged steel return bends which comprises press forging heated billets to form respective return bend blanks each having angularly disposed body and boss portions, hollowing the said boss and body portions of said blanks to form connecting passageways in the respective blanks, assembling a plurality of the thus hollowed blanks with their bosses in abutting relation, welding said plurality of blanks toproduce a unitary return bend .hav-

ing a passageway therein, said passageway being made up of a plurality of branches that open to the outside of the return bend and each pair of adjacent branches being connected by a connecting passageway that opens only in said pair of branches, effecting a broaching action within said .connecting passageway from one end thereof to remove the welding flash therein by exerting a force to cause the movement of the broaching means therein, and effecting an aligned control of the breaching action from he end of ,said connecting passageway towards j' hich the broaching action is advanced.

2. The process of manufacturing press forged steel return bends which comprises press forging heated billets to form respective return bend blanks each having angularly disposed body and boss portions, hollowing the said boss and body portions of said blanks to form connecting passageways in the respective blanks, assembling a plurality of the thus hollowed blanks with their bosses in abutting relation, flash resistance Welding said plurality of blanks to produce a unitary return bend having a passageway therein, said passageway being made up of a plurality of branches that open to the outside of the return bend and each pair of adjacent branches being connected by a connecting passageway that opens only in said pair of branches,

effecting a broaching action within saidconnecting passageway from one end thereof to remove the welding flash therein by exerting a force through one of the branches into which said connecting passageway opens and changing the direction of the exerted force to cause a movement of the broaching means in said connecting passageway, and effecting an alignment control of the broaching action from the end of the said connecting passageway towards which the broaching action is advanced.

3. The process of manufacturing press forged steel return bends of predetermined distance between centers which comprises press forging heated billets to form respective return bend lanks each having angularly disposed body and boss portions, each boss portion extending from the center of its respective body portion in excess of one half of the predetermined distance between centers, hollowing the said boss and body portions of said blanks to form connecting passageways in the respective blanks, assembling a plurality of the thus hollowed blanks with their bosses in abutting relation, flash resistance welding said plurality of blanks to produce a unitary return bend of predetermined distance between centers with a passageway therein, said passageway being made up of a plurality of branches that open to the outside of the return bend and each pair of adjacent branches being connected by a connecting passageway that opens only in said pair of branches, effecting a broaching action within said connecting passageway from one end thereof to remove the welding flash therein by exerting a force to cause the movement of broaching means therein, and effecting an alignment control of the broaching action from the end of the said connecting passageway towards which the broaching action is advanced.

4. The process of manufacturing press forged steel return bends of predetermined distance between centers which comprises press forging heated billets to form respective return bend blanks each having angularly disposed body and boss portions, each boss portion extending from the center of its respective body portion in excess of one half of the predetermined distance between centers, hollowing the said boss and body portions of said blanks to form connecting passageways in the respective blanks, assembling a plurality of the thus hollowed blanks with their bosses in abutting relation, flash resistance welding said plurality of blanks to produce a unitary return bend of predetermined distance between centers with a passageway therein, said passageway being made up of'a plurality of branches that open to the outside of the return bend and each pair of adjacent branches being connected by a connecting passageway that opens only in said pair of branches, effecting a broaching action within said connecting passageway from one end thereof to remove the welding-flash therein by exerting a force through one of'the branches into which said connecting passageway opens and changing the direction of the exerted force to cause a movement of the broaching means in said connecting passageway, and effecting an alignment control of the broaching action from the end of the said connecting passageway towards which the broaching action is advanced.

ROBERT K. HOPKINS. 

